Files
apfstests/tests/btrfs/192
T
Qu Wenruo d0f42706da btrfs: Check snapshot creation and deletion with dm-logwrites
We have generic dm-logwrites with fsstress test case (generic/482),
but it doesn't cover fs specific operations like btrfs snapshot
creation and deletion.

Furthermore, that test is not heavy enough to bump btrfs tree height
by its short runtime.

And finally, btrfs check doesn't consider dirty log as an error,
unlike ext*/xfs, that's to say we don't need to mount the fs to
replay the log, but just running btrfs check on the fs is enough.

So introduce a similar test case but for btrfs only.

The test case will stress btrfs by:
- Use small nodesize to bump tree height
- Create a base tree which is already high enough
- Trim tree blocks to find possible trim bugs
- Call snapshot creation and deletion along with fsstress

Also it includes certain workaround for btrfs:
- Allow _log_writes_mkfs to accept extra mkfs options
- Use no-holes feature
  To avoid missing hole file extents.
  Although that behavior doesn't follow the on-disk format spec, it
  doesn't cause data loss. And will follow the new on-disk format spec
  of no-holes feature, so it's better to workaround it.

And an optimization for btrfs only:
- Use replay-log --fsck/--check command
  Since dm-log-writes records bios sequentially, there is no way to
  locate certain entry unless we iterate all entries.
  This is becoming a big performance penalty if we replay certain a
  range, check the fs, then re-execute replay-log to replay another
  range.

  We need to records the previous entry location, or we need to
  re-iterate all previous entries.

  Thankfully, replay-log has already address it by providing --fsck and
  --check command, thus we don't need to break replay-log command.

Please note, for fast storage (e.g. fast NVME or unsafe cache mode),
it's recommended to use log devices larger than 15G, or we can't
record the full log of just 30s fsstress run.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
2019-09-15 12:23:53 +08:00

176 lines
4.2 KiB
Bash
Executable File

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2019 SUSE Linux Products GmbH. All Rights Reserved.
#
# FS QA Test 192
#
# Test btrfs consistency after each FUA for a workload with snapshot creation
# and removal
#
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
here=`pwd`
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
cd /
kill -q $pid1 &> /dev/null
kill -q $pid2 &> /dev/null
"$KILLALL_PROG" -q $FSSTRESS_PROG &> /dev/null
wait
_log_writes_cleanup &> /dev/null
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
. ./common/attr
. ./common/dmlogwrites
# remove previous $seqres.full before test
rm -f $seqres.full
# real QA test starts here
# Modify as appropriate.
_supported_fs btrfs
_supported_os Linux
_require_command "$KILLALL_PROG" killall
_require_command "$BLKDISCARD_PROG" blkdiscard
_require_btrfs_fs_feature "no_holes"
_require_btrfs_mkfs_feature "no-holes"
_require_log_writes
_require_scratch
_require_attrs
# We require a 4K nodesize to ensure the test isn't too slow
if [ $(get_page_size) -ne 4096 ]; then
_notrun "This test doesn't support non-4K page size yet"
fi
runtime=30
nr_cpus=$("$here/src/feature" -o)
# cap nr_cpus to 8 to avoid spending too much time on hosts with many cpus
if [ $nr_cpus -gt 8 ]; then
nr_cpus=8
fi
fsstress_args=$(_scale_fsstress_args -w -d $SCRATCH_MNT -n 99999 -p $nr_cpus \
$FSSTRESS_AVOID)
_log_writes_init $SCRATCH_DEV
# Discard the whole devices so when some tree pointer is wrong, it won't point
# to some older valid tree blocks, so we can detect it.
$BLKDISCARD_PROG $LOGWRITES_DMDEV > /dev/null 2>&1
# Use no-holes to avoid warnings of missing file extent items (expected
# for holes due to mix of buffered and direct IO writes).
# And use 4K nodesize to bump tree height.
_log_writes_mkfs -O no-holes -n 4k >> $seqres.full
_log_writes_mount
$BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/src > /dev/null
mkdir -p $SCRATCH_MNT/snapshots
mkdir -p $SCRATCH_MNT/src/padding
random_file()
{
local basedir=$1
echo "$basedir/$(ls $basedir | sort -R | tail -1)"
}
snapshot_workload()
{
trap "wait; exit" SIGTERM
local i=0
while true; do
$BTRFS_UTIL_PROG subvolume snapshot \
$SCRATCH_MNT/src $SCRATCH_MNT/snapshots/$i \
> /dev/null
# Do something small to make snapshots different
rm -f "$(random_file $SCRATCH_MNT/src/padding)"
rm -f "$(random_file $SCRATCH_MNT/src/padding)"
touch "$(random_file $SCRATCH_MNT/src/padding)"
touch "$SCRATCH_MNT/src/padding/random_$RANDOM"
i=$(($i + 1))
sleep 1
done
}
delete_workload()
{
trap "wait; exit" SIGTERM
while true; do
sleep 2
$BTRFS_UTIL_PROG subvolume delete \
"$(random_file $SCRATCH_MNT/snapshots)" \
> /dev/null 2>&1
done
}
# Replay and check each fua/flush (specified by $2) point.
#
# Since dm-log-writes records bio sequentially, even just replaying a range
# still needs to iterate all records before the end point.
# When number of records grows, it will be unacceptably slow, thus we need
# to use relay-log itself to trigger fsck, avoid unnecessary seek.
log_writes_fast_replay_check()
{
local check_point=$1
local blkdev=$2
local fsck_command="$BTRFS_UTIL_PROG check $blkdev"
local ret
[ -z "$check_point" -o -z "$blkdev" ] && _fail \
"check_point and blkdev must be specified for log_writes_fast_replay_check"
$here/src/log-writes/replay-log --log $LOGWRITES_DEV \
--replay $blkdev --check $check_point --fsck "$fsck_command" \
&> $tmp.full_fsck
ret=$?
tail -n 150 $tmp.full_fsck > $seqres.full
[ $ret -ne 0 ] && _fail "fsck failed during replay"
}
xattr_value=$(printf '%0.sX' $(seq 1 3800))
# Bumping tree height to level 2.
for ((i = 0; i < 64; i++)); do
touch "$SCRATCH_MNT/src/padding/$i"
$SETFATTR_PROG -n 'user.x1' -v $xattr_value "$SCRATCH_MNT/src/padding/$i"
done
_log_writes_mark prepare
snapshot_workload &
pid1=$!
delete_workload &
pid2=$!
"$FSSTRESS_PROG" $fsstress_args > /dev/null &
sleep $runtime
"$KILLALL_PROG" -q "$FSSTRESS_PROG" &> /dev/null
kill $pid1 &> /dev/null
kill $pid2 &> /dev/null
wait
_log_writes_unmount
_log_writes_remove
log_writes_fast_replay_check fua "$SCRATCH_DEV"
echo "Silence is golden"
# success, all done
status=0
exit